Ling 240: Language and Mind Acquisition of Phonology

English [p h ] [b] [p]

Hindi [p] [p h ] [b]

English Japanese English Japanese [l] [r] [l] [r]

Voice onset time VOT = the time between the release of a stop and the voicing of a following vowel VOT = the time between the release of a stop and the voicing of a following vowel

Voice Onset Time (VOT) 60 msec

Discrimination 0ms 20ms 40ms 20ms 40ms 60ms D T D TT D

Categorization of speech sounds We group sounds into categories, despite physical variability We group sounds into categories, despite physical variability Some physical differences are mentally represented as “not different”; others as “different” Some physical differences are mentally represented as “not different”; others as “different” Is categorical perception innate? Is categorical perception innate? How are mental categories acquired? How are mental categories acquired?

High Amplitude Sucking Procedure Initially sucking rate increases (novelty) Then decreases Decline in response = habituation LSCP Infant Lab

High Amplitude Sucking Procedure When sucking rate declines to a set point (habituation criterion), auditory stimulus is changed LSCP Infant Lab

High Amplitude Sucking Procedure If sucking rate increases, then we know the infant has detected the change The renewed response = dishabituation LSCP Infant Lab

Newborns are universal listeners  Infants perceive speech categorically  Newborns are sensitive to almost every phonological distinction yet tested

Newborns are universal listeners  In contrast, adults have difficulty discriminating speech sounds that are not contrastive in their native language

Hindi contrasts [dããt]tooth [dããt]tooth [DããT]scold, be angry with [DããT]scold, be angry with [taal]‘musical note’ [taal]‘musical note’ [Taal]‘to ignore’ [Taal]‘to ignore’

Newborns are universal listeners  English infants can distinguish Hindi /d/ and /D/  Japanese infants can distinguish between /l/ and /r/

Studies by Werker et al Infants are universal listeners but adults can’t discriminate non-native phonemic contrasts Then there must be a decline across age Questions: Questions: what is the role of experience? what is the role of experience? when exactly does this decline happen? when exactly does this decline happen? is this decline a critical period effect? is this decline a critical period effect?

Testing Across the Lifespan young infants older infants children and adults Conditioned Head Turn Paradigm Habituation (High Amplitude Sucking) Just ask them: “Same or different?”

Visual Reinforcer (VR) Toy that lights up and moves at the experimenter’s command Controls for sound stimuli and the VR

Conditioned Head Turn Child hears Stimulus 1 (/ba/) repeatedly Then Stimulus 2 is presented (/da/) If child detects difference, he should turn to look at the visual reinforcer when the stimulus changes If child does not detect it, he shouldn’t turn

Conditioned Head Turn Paradigm Kuhl Lab, U Washington, 1992

Werker 1995 Testing /ba/ vs. /da/ /Ta/ vs. /ta/ /t h a/ vs. /d h a/ Subjects: Hindi adults English Adults English 6-8 month-olds

Werker 1995 /ba/ vs. /da/Hindi and English /Ta/ vs. /ta/Only Hindi /t h a/ vs. /d h a/Only Hindi

Results Werker, 1995

Questions When does decline in performance take place? When does decline in performance take place? What exactly is responsible for the decline? What exactly is responsible for the decline? Does Critical Period play a role? Does Critical Period play a role?

General Methodology question We observe that infants behave one way and adults behave another way. Goal: We want to know what changes at what point in time. Goal: We want to know what changes at what point in time. What are some ways of obtaining this data? What are some ways of obtaining this data?

Werker & Tees 1984  Test infants of different ages (Cross-sectional)  Test the same group of infants at different points in time (Longitudinal) 6-8 months6-8 months 8-10 months8-10 months month10-12 month

Werker & Tees 1984: Nthlakampx Native American language spoken by about 200 speakers (in 1984) in British Columbia—also known as Thompson or Salish Native American language spoken by about 200 speakers (in 1984) in British Columbia—also known as Thompson or Salish Nthlakampx glottalized velar vs glottalized uvular ejectives Nthlakampx glottalized velar vs glottalized uvular ejectives [‘ki] vs [‘qi] [‘ki] vs [‘qi] Velar ‘k.. Velar ‘k.. Uvular ‘q… Uvular ‘q…

Results Werker & Tees, 1984

Werker studies: Conclusion Ability to perceive non-native contrasts declines in 1st year Werker and Tees 1984

What is responsible for the change? How do babies become adults?

First proposal: Maintenance/Loss Hypothesis role of experience is to maintain perceptual sensitivities role of experience is to maintain perceptual sensitivities lack of exposure leads to loss of perceptual ability lack of exposure leads to loss of perceptual ability

Maintenance/Loss Model Ability Time Experience 1 year No experience

Problems for the Maintenance/Loss Hypothesis Prediction? Prediction? Decline in sensitivity following lack of exposure should be permanent and absolute

Problems for the Maintenance/Loss Hypothesis Predictions are not borne out: (1) Adults CAN perceive non-native contrasts in (perceived) non-speech tasks in (perceived) non-speech tasks Zulu clicks Zulu clicks The link to listen to Zulu clicks sounds in isolation (not syllables) sounds in isolation (not syllables)

Problems for the Maintenance/Loss Hypothesis Predictions are not borne out: (2) Children older than 12 months can move to a new country and acquire native phonology Children older than 12 months can move to a new country and acquire native phonology

Alternative Hypothesis: Functional Reorganization no absolute hardware changes in auditory system no absolute hardware changes in auditory system development of a linguistic system that imports a subset of the contrasts from the auditory system development of a linguistic system that imports a subset of the contrasts from the auditory system

Conclusions So, what changes during the first year? So, what changes during the first year? Answer: the baby starts to acquire a linguistic system As babies acquire a linguistic system (words) in their first year, they “learn” which distinctions need to be represented in that system As babies acquire a linguistic system (words) in their first year, they “learn” which distinctions need to be represented in that system